Particulate air pollution is solid or liquid particles suspended in the air. It can come from sources including fumes, burning vegetation, and dirt. Exposure to this type of pollution has been linked with diabetes, worsening mental health in dementia patients, and an increased risk of certain types of cancer. A new study further backs up its link to cancer.
Researchers at the National Institutes of Health recently studied how fine particulate matter (PM2.5) impacts breast cancer incidence. In a study involving more than half a million Americans, the team found that living in areas with higher concentrations of PM2.5 was linked with a higher risk of developing estrogen receptor-positive (ER+) breast cancer, the type most commonly diagnosed in the United States. As poor air quality days due to wildfire smoke increase, the findings have implications for many people.
Dr. Alexandra White, lead author and head of the Environment and Cancer Epidemiology Group at the National Institute of Environmental Health Sciences, says, “We observed an 8% increase in breast cancer incidence for living in areas with higher PM2.5 exposure. Although this is a relatively modest increase, these findings are significant given that air pollution is a ubiquitous exposure that impacts almost everyone. These findings add to a growing body of literature suggesting that air pollution is related to breast cancer.”
The findings, published in the Journal of the National Cancer Institute, involved data from more than 500,000 men and women from the NIH-AARP Diet and Health Study. People from six states, along with the Atlanta and Detroit metro areas, enrolled in the study between 1995 and 1996. The women involved had an average age of 62 and mostly identified as non-Hispanic white. Over a follow-up period of about 20 years, 15,870 participants were diagnosed with breast cancer.
The researchers looked at the historical average PM2.5 concentrations at each participant’s home, focusing on the readings from 10 to 15 years prior to the study’s enrollment, as cancers can take years to develop.
They also broke down the breast cancer cases into two tumor subtypes: estrogen receptor-positive (ER+) and estrogen receptor-negative (ER-) to see if numbers differed between the two. They did, with ER+ cases seeing an uptick with high concentrations of PM2.5, but ER- cases not seemingly impacted. The team says this could have something to do with PM2.5 causing endocrine disruption.
Though the findings point to more of the possible harms caused by particulate air pollution, the researchers say further study is needed, including on how pollution and breast cancer are linked in different regions. They say the type of particles that women are exposed to could possibly have different impacts on breast cancer risk.
Another recent study also found that PM2.5 was linked with a higher incidence of colorectal and prostate cancers. This comes as research finds more than 63 million Americans live in areas with daily spikes in particulate pollution. If you’d like to help address this problem, consider signing this petition asking the federal government to strengthen the Clean Air Act.